JP2008210829A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided heat dissipation semiconductor device in which first heat dissipation plate out of first and second heat dissipation plates consists of a plurality of heat dissipation plates having different potentials, and the grease provided on one heat dissipation plate having a different potential is prevented from touching the grease provided on the other heat dissipation plate when the heat dissipation surfaces of the first and second heat dissipation plates are touched to a cooler. <P>SOLUTION: The first heat dissipation plate 30 is constituted as an assembly of a first left heat dissipation plate 31 and a first right heat dissipation plate 32 having different potentials, and a groove 80 is provided in the surface of a mold resin 70 located between these first left heat dissipation plate 31 and the first right heat dissipation plate 32 to lie between these heat dissipation plates 31 and 32 having different potentials. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor device in which a semiconductor element is interposed between a pair of heat sinks facing each other on the inner surface and sealed with a mold resin so as to dissipate heat from each of the heat sinks, a so-called double-sided heat dissipation type semiconductor device. In particular, the present invention relates to a structure in which at least one of the pair of heat sinks is composed of a plurality of heat sinks having different potentials.

  Conventionally, as this type of semiconductor device, a plurality of semiconductor elements are sandwiched between a first heat radiating plate and a second heat radiating plate which are opposed to each other on their inner surfaces, and the first and second heat radiating plates are interposed. The board and each semiconductor element are electrically and thermally connected via solder or the like, and the first and second heat radiating plates and the semiconductor element are encapsulated in a mold resin. (For example, see Patent Document 1).

  In such a semiconductor device, the outer surface, which is the surface opposite to the inner surfaces of the first and second heat radiating plates, is configured as a heat radiating surface that radiates heat, and this heat radiating surface is exposed from the mold resin. Yes.

This semiconductor device is applied to, for example, an inverter of a vehicle, but in practical use, grease such as silicone grease is applied to the heat radiating surface of each heat radiating plate, and then contacted with the cooling device through this. It is common.
Japanese Patent No. 3525832

  By the way, in this semiconductor device, each of the 1st and 2nd heat sink is electrically connected with respect to the some semiconductor element pinched | interposed into the said 1st and 2nd heat sink. .

  For this reason, each of the first and second heat radiating plates is applied with a potential equivalent to the potential applied to the circuit constituted by these semiconductor elements. For example, conventionally, a switching circuit in which IGBT and FWD are connected in reverse parallel as a semiconductor element is configured, and an inverter voltage is applied to each of the heat sinks.

  Here, when a plurality of circuits are configured by the semiconductor elements between the first and second heat radiating plates, one or both of the first and second heat radiating plates have a plurality of heat radiating potentials different from each other. It will be configured as an aggregate of plates.

  In this case, each of the plurality of heat dissipation plates having different potentials is sealed with the mold resin while exposing the heat dissipation surface. However, since each heat dissipation surface is provided with grease as described above, they have different potentials. It is necessary to ensure a creepage distance according to the insulation reliability of the grease between the heat radiation surfaces. In this case, the outer shape of the mold resin is increased, which tends to hinder downsizing of the apparatus.

  Alternatively, as another method, it is necessary to prevent the grease applied to one heat dissipation surface and the grease applied to the other heat dissipation surface from contacting each other between adjacent heat dissipation plates having different potentials.

  The present invention has been made in view of the above problems, and in a double-sided heat radiation type semiconductor device in which at least one of the first and second heat radiation plates is constituted by a plurality of heat radiation plates having different potentials, a grease is provided. When the heat radiating surfaces of the first and second heat radiating plates are brought into contact with the cooling device, the contact between the grease provided on one of the heat radiating plates having different potentials and the grease provided on the other can be prevented. The purpose is to do.

  In order to achieve the above object, according to the present invention, in a double-sided heat radiation type semiconductor device, at least one of the first and second heat radiation plates (30, 40) is replaced with a plurality of heat radiation plates (31, 32) having different potentials. ) And a groove (80) lying on the surface of the mold resin (70) positioned between the heat dissipation plates (31, 32) having different potentials and lying between the heat dissipation plates (31, 32) having different potentials. , 84).

  According to that, since the groove | channel (80, 84) which lies between the heat sinks (31, 32) from which an electric potential differs is provided in the surface of mold resin (70), compared with the conventional case which does not provide the said groove | channel. As the creepage distance between the radiator plates (31, 32) having different potentials increases, the grease (210) applied to one of the radiator plates (31, 32) having different potentials overflows to the other side. Since the grooves (80, 84) are also received, it is possible to prevent the grease provided on one side of the heat radiating plates (31, 32) having different potentials from contacting with the grease provided on the other side.

  Here, on the surface of the mold resin (70) positioned between the heat radiating plates (31, 32) having different potentials, the direction in the direction orthogonal to the direction in which the heat radiating plates (31, 32) having different potentials face each other. A groove (80) may be provided so as to continuously traverse both ends of the surface. According to this, it is preferable for facilitating the discharge of the foreign matter that has entered the groove (80).

  Further, if the groove (80) is constituted by a plurality of grooves (81 to 83) provided in parallel, the receiving of the overflowing grease (210) and the creeping distance can be reduced as compared with the case of one groove. Easy to secure.

  In particular, it is preferable that the plurality of grooves (81 to 83) are formed of different depths. In this case, specifically, at least three grooves (81 to 83) are provided in parallel, and are located on the center side of the plurality of grooves (81 to 83). The groove (82) may be deeper than the grooves (81, 83) located on both sides of the groove (82) located on the center side.

  Moreover, when the 1st heat sink (30) is comprised from the several heat sink (31, 32) from which an electric potential differs among 1st and 2nd heat sinks (30, 40), a groove | channel is mold resin. (70), the mold resin (70) and the second resin from the first heat radiating plate (30) toward the second heat radiating plate (40) at a portion located between the heat radiating plates (31, 32) having different potentials. You may comprise as a through-hole (84) which penetrates this heat sink (40).

  According to this, since the groove is configured as a through hole (84), it is easy to discharge foreign matter that has entered the groove.

  Further, a step is formed on the inner surface of the through hole (84) close to the first heat radiating plate (30) so as to expand toward the opening on the first heat radiating plate (30) side of the through hole (84). You may provide the level | step-difference part (85) which makes | forms. According to this, the grease (210) flowing into the through hole (84) as a groove can be received by the step portion (85).

  Further, the connecting portion (40d) for connecting the through holes (84) as the grooves in the second heat radiating plate (40) is extended outward from the heat radiating surface (40b) of the second heat radiating plate (40). The connecting portion (40d) may be sealed with a mold resin (70).

  According to this, since the connecting portion (40d) in the second heat radiating plate (40) projects outward from the heat radiating surface (40b) of the second heat radiating plate (40), the through hole (84) Can be increased as much as possible, which is preferable for increasing the heat dissipation surface (30b) of the first heat dissipation plate (30).

  In addition, the code | symbol in the bracket | parenthesis of each means described in the claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
FIG. 1 is a diagram showing a schematic plan configuration of a semiconductor device 100 according to the first embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view along the line AA in FIG. Here, FIG. 1 is a top plan view of FIG. 2, and FIG. 3 is a bottom plan view of FIG. This semiconductor device 100 is mounted on a vehicle such as an automobile, for example, and is applied as a device for driving a vehicle electronic device.

  As shown in FIGS. 1 to 3, the semiconductor device 100 includes four semiconductor elements 10 and 20 arranged in a plane. Here, the four semiconductor elements 10 and 20 are a set of one set of one first semiconductor element 10 and one second semiconductor element 20, one set on the left and right, for a total of two sets. It has become.

  For example, the first semiconductor element 10 is an IGBT (insulated gate bipolar transistor) 10, and the second semiconductor element 20 is an FWD (flywheel diode) 20. Each set of IGBT 10 and FWD 20 constitutes a switching circuit.

  Both surfaces of these semiconductor elements 10 and 20 are sandwiched between first and second heat radiation plates 30 and 40 that function as electrodes and heat radiation members of the semiconductor elements 10 and 20. In the present embodiment, in FIG. 2, the heat sink 30 located on the upper side among these heat sinks 30 and 40 is referred to as the first heat sink 30, and the heat sink 40 located on the lower side is the second heat sink 40. And

  These heat sinks 30 and 40 are made of a general lead frame material or the like, and are made of, for example, a plate material obtained by applying nickel plating to a copper alloy. Here, the 1st and 2nd heat sinks 30 and 40 are arrange | positioned facing each other's inner surfaces 30a and 40a. In each of the first and second heat radiating plates 30 and 40, outer surfaces 30b and 40b, which are surfaces opposite to the inner surfaces 30a and 40a, are configured as heat radiating surfaces 30b and 40b.

  In the semiconductor device 100 of the present embodiment, the second heat radiating plate 40 is made of a single plane substantially rectangular plate material, but the first heat radiating plate 30 corresponds to the two sets of semiconductor elements 10 and 20 described above. The two heat sinks 31 and 32 have a substantially rectangular plane. In the following, corresponding to the left-right direction in FIGS. 1 to 3, of the two first heat sinks 31 and 32, the left one in FIGS. This is referred to as the first right heat radiating plate 32.

  The semiconductor elements 10 and 20 are sandwiched between the inner surfaces 30a and 40a of the first and second heat radiating plates 30 and 40, and both the semiconductor elements 10 and 20 and the first and second heat radiating plates. The inner surfaces 30 a and 40 a of the terminals 30 and 40 are electrically and thermally connected via the solder 50 and the block body 60.

  The block body 60 has a rectangular block shape excellent in electrical conductivity and thermal conductivity, and is usually made of copper, but molybdenum or the like may be used. The semiconductor elements 10, 20, the block body 60, and the inner surfaces 30 a, 40 a of the first and second heat radiating plates 30, 40 are joined and fixed by solder 50, respectively.

  Here, the solder 50 that connects the above-described parts can be a solder material that is employed in the field of general semiconductor devices. For example, a lead-free solder such as a tin-copper alloy solder is employed. Can do.

  1 to 3, in the semiconductor device 100 of the present embodiment, the pair of heat sinks 30 and 40, the semiconductor elements 10 and 20 and the block body 60 sandwiched between the heat sinks 30 and 40, are molded resin 70. It is sealed by. The mold resin 70 is made of a normal mold material such as an epoxy resin, and is produced by resin molding using a molding die.

  Further, as shown in FIG. 1, the heat radiation surfaces 30 b and 40 b are exposed from the mold resin 70 in the first and second heat radiation plates 30 and 40, respectively. Thereby, in the semiconductor device 100 of the present embodiment, heat is radiated through the first heat radiating plate 30 and the second heat radiating plate 40 on both surfaces of the first and second semiconductor elements 10 and 20. It has a double-sided heat dissipation configuration.

  The first and second heat sinks 30 and 40 are electrically connected to electrodes (not shown) on the respective surfaces of the semiconductor elements 10 and 20 via the solder 50 and the block body 60. For example, the first heat radiating plate 30 and the second heat radiating plate 40 serve as the collector side electrode of the IGBT 10, the cathode side electrode of the FWD 20, the emitter side electrode of the IGBT 10, and the anode side electrode of the FWD 20.

  And the terminal which is not illustrated is integrally formed with each of the 1st heat sink 30 and the 2nd heat sink 40, and each heat sink 30 and 40 can be electrically connected with the exterior through this terminal. It has become.

  Although not shown, control terminals made of a lead frame separate from the heat sinks 30 and 40 are provided around the respective IGBTs 10 in the mold resin 70. The control terminal is configured as a gate terminal of the IGBT 10 or various inspection terminals, and is electrically connected to the IGBT 10 through a bonding wire (not shown) in the mold resin 70.

  In such a configuration, the block body 60 interposed between the second heat radiating plate 40 and the semiconductor elements 10 and 20 maintains the height of the wire when wire bonding is performed between the IGBT 10 and the control terminal. Therefore, the height between the wire bonding surface of the IGBT 10 and the first and second heat radiation plates 30 and 40 is ensured.

  As described above, the semiconductor device 100 according to the present embodiment includes a plurality of semiconductor elements 10 and 20 between the first heat sink 30 and the second heat sink 40 facing each other on the inner surfaces 30a and 40a. The first and second radiator plates 30 and 40 and the respective semiconductor elements 10 and 20 are electrically and thermally connected to each other.

  Further, as described above, each group of IGBT 10 and FWD 20 constitutes a switching circuit. However, the first radiator plates 31 and 32 having different potentials are electrically connected to each group. Yes. Thereby, for example, a current flows from the first left heat radiating plate 31 toward the first right heat radiating plate 32 through a circuit inside the mold resin 70.

  That is, in the semiconductor device 100, the second heat radiating plate 40 is configured as one heat radiating plate having the same potential, but the first heat radiating plate 30 includes two heat radiating plates having different potentials. 31, 32, that is, an aggregate of the first left heat radiating plate 31 and the second right heat radiating plate 32.

  In the present embodiment, the surfaces of the mold resin 70 positioned between the first left radiator plate 31 and the second right radiator plate 32 having different potentials are disposed on the surfaces of the radiator plates 31 and 32 having different potentials. A groove 80 is provided so as to lie in between.

  Here, one groove 80 may be provided, but in the illustrated example, the groove 80 includes three grooves 81 to 83 provided in parallel. That is, the groove 80 of this example is configured as an aggregate of three grooves 81 to 83.

  These three grooves 81 to 83 may be grooves having the same depth, but here, each of the grooves 81 to 83 is configured by different depths. That is, as shown in FIG. 2, the groove 82 located at the center of the three grooves 81 to 83 is deeper than the grooves 81 and 83 located on both sides thereof.

  Further, as shown in FIG. 1, the groove 80 of the present embodiment has a direction in which the heat radiating plates 31 and 32 having different potentials face each other on the surface of the mold resin 70 positioned between the heat radiating plates 31 and 32 having different electric potentials. Is provided continuously between the both ends so as to cross both ends of the surface in the direction orthogonal to the vertical direction (vertical direction in FIG. 1).

  That is, on the surface of the mold resin 70 located between the heat radiation plates 31 and 32 having different potentials, the three grooves 81 to 81 having a cross-sectional shape as shown in FIG. 83 is formed. The formation of the groove 80 in the mold resin 70 can be realized by forming the mold resin 70, cutting, or the like.

  Next, a method for manufacturing the semiconductor device 100 will be described. First, a workpiece without the mold resin 70 in FIGS. 1 to 3, that is, a workpiece sealed with the mold resin 70 is prepared.

  The workpiece is formed by laminating and joining the first heat radiating plate 30, the semiconductor elements 10 and 20, the block body 60, and the second heat radiating plate 40 via the solder 50, and wire between the control terminal and the IGBT 10. It is produced by bonding.

  Next, this work is sealed with a mold resin 70. This resin sealing is performed using a molding die used in a general transfer molding method or the like. After completion of this resin sealing step, this embodiment is performed by performing a step of removing resin burrs adhering to the heat radiating surfaces 30b, 40b of the first and second heat radiating plates 30, 40 as necessary. The semiconductor device 100 is completed.

  The semiconductor device 100 is applied to, for example, a vehicle inverter. In this case, like the general semiconductor device of this type, it is attached to the cooling device via electrically insulating grease.

  FIG. 4 is a schematic cross-sectional view showing a state in which the semiconductor device 100 is attached to the cooling device 200. In the semiconductor device 100 of this embodiment, grease 210 is applied to the outside of the heat radiation surfaces 30b and 40b of the first and second heat radiation plates 30 and 40, and an insulating substrate 220 is further provided.

  Here, the grease 210 is an electrically insulating material made of silicone grease or the like, and the insulating substrate 220 is an electrically insulating plate material made of alumina or silicon nitride. Then, the cooling device 200 is pressurized and brought into contact with the outside of the heat radiating surfaces 30b and 40b via the grease 210 and the insulating substrate 220. As this cooling device 200, for example, cooling water flows inside, and a general device that effectively dissipates heat from the semiconductor device 100 can be adopted.

  Here, foreign substances tend to be mixed into the grease 210 during the assembly process, and the electrical insulation of the grease 210 may be impaired due to the mixing of the foreign substances. Therefore, as described above, between the heat radiation surface 30b of the first left heat radiation plate 31 and the heat radiation surface 30b of the first right heat radiation plate 32 having different potentials, the grease 210 applied to one heat radiation surface. It is necessary to prevent the grease 210 applied to the other heat radiation surface from contacting.

  In view of this point, according to the present embodiment, the groove 80 is provided on the surface of the mold resin 70 located between the radiator plates 31 and 32 having different potentials. According to this, since the groove 80 lies between the heat radiation plates 31 and 32 having different potentials, the creepage distance between the heat radiation plates 31 and 32 having different potentials is larger than in the conventional case where the grooves are not provided. Become.

  In addition, according to the present embodiment, as shown in FIG. 3, when the semiconductor device 100 is assembled via the grease 210, the grease 210 applied to one of the radiator plates 31 and 32 having different potentials. However, even if it overflows to the other side, it is received by the groove 80.

  In this embodiment, the groove 80 is constituted by an aggregate of three grooves 81 to 83 arranged in parallel, and the groove 82 located in the center is deep, and the grooves 81 and 83 located on both sides thereof are shallow. is doing. Therefore, as shown in FIG. 4, the shallow grooves 81 and 83 on both sides serve to receive the overflowing grease 210, and the deep groove 82 in the center serves to ensure the creepage distance. Become.

  Thus, in this embodiment, the groove | channel 80 is made into the aggregate | assembly of several groove | channels 81-83 from which depth differs, The function which receives the grease 210 in each of several groove | channel, and the said creepage distance are ensured. Designs with shared functions can be performed. In that respect, it is preferable compared to the case where the groove 80 is configured as one groove.

  Thus, according to the present embodiment, due to the action of the groove 80 described above, the heat radiating surfaces 30b and 40b of the first and second heat radiating plates 30 and 40 in the semiconductor device 100 are provided to the cooling device 200 via the grease. When contacting, the grease 210 provided on the heat radiating surface 30b of the first left heat radiating plate 31 and the grease 210 provided on the heat radiating surface 30b of the first right heat radiating plate 32 can be prevented.

  Further, as shown in FIG. 1, the three grooves 81 to 83, that is, the groove 80 of the present embodiment, have different potentials on the surface of the mold resin 70 located between the heat radiation plates 31 and 32 having different potentials. The heat radiating plates 31 and 32 are continuously provided between the both ends so as to cross both ends of the surface in the direction orthogonal to the facing direction.

  For example, in the double-sided heat dissipation type structure as in the present embodiment, after molding with the mold resin 70, the front and back heat dissipating surfaces 30b, 40b are processed by cutting or the like to obtain a flatness of the heat dissipating surfaces 30b, 40b. By ensuring the accuracy of parallelism and thickness, it is possible to ensure heat dissipation.

  Here, when the cutting waste enters the groove 80, it is necessary to remove it. However, according to the present embodiment, the cross-sectional shape of the groove 80 remains as it is at both ends of the surface of the mold resin 70. It is exposed to the outside.

  Therefore, the foreign matter that has entered the groove 80 can be flowed out from both ends of the groove 80 by cleaning, air injection, or the like. Therefore, according to the present embodiment, the foreign matter in the groove 80 can be easily discharged, which is preferable in terms of ensuring the insulation reliability of the groove 80.

(Second Embodiment)
FIG. 5 is a diagram showing a schematic plan configuration of a semiconductor device 101 according to the second embodiment of the present invention, and FIG. 6 is a schematic cross-sectional view along the line BB in FIG. Here, FIG. 5 is a top plan view of FIG. 6, and FIG. 7 is a bottom plan view of FIG. 6. The difference from the first embodiment will be mainly described.

  Also in the semiconductor device 101 of the present embodiment, the second heat radiating plate 40 is configured as one heat radiating plate having the same potential, and the first heat radiating plate 30 is a first left heat radiating plate 31 having a different potential. And the second right heat radiating plate 32.

  Here, in the present embodiment, as in the first embodiment, a groove 84 lying between the radiator plates 31 and 32 having different potentials is provided on the surface of the mold resin 70. However, the groove 80 of the first embodiment is configured as a recess having a closed bottom.

  On the other hand, the groove 84 according to the present embodiment is formed from the first heat radiating plate 30 toward the second heat radiating plate 40 at a portion located between the heat radiating plates 31 and 32 having different potentials in the mold resin 70. It is configured as a through hole 84 that penetrates both the 70 and the second heat dissipation plate 40.

  Here, as shown in FIGS. 5 to 7, in the second heat radiating plate 40, a hole 40 c that penetrates from the inner surface 40 a to the heat radiating surface 40 b, that is, an opening 40 c that penetrates the second heat radiating plate 40 in the thickness direction. Is provided. The opening 40c can be formed on the second heat radiating plate 40 by pressing or the like.

  The through hole 84 as the groove has a shape that penetrates from the mold resin 70 through the opening 40 c to the heat radiating surface 40 b of the second heat radiating plate 40. Further, the through hole 84 has a stepped inner hole shape having a stepped portion 85 on the inner surface on the first heat radiating plate 30 side.

  That is, by providing the stepped portion 85 on the inner surface of the through hole 84 near the first heat radiating plate 30, the opening on the first heat radiating plate 30 side of the through hole 84 is expanded with the stepped portion 85 as a boundary. It has become.

  Moreover, the groove | channel 80 (refer FIG. 1) of the said 1st Embodiment is the direction where the said heat sinks 31 and 32 from which the said electric potential opposes on the surface of the mold resin 70 located between the heat sinks 31 and 32 from which an electric potential differs. However, the through hole 84 as a groove in the present embodiment is not provided in the both end portions but provided in a part between the both end portions. It has been.

  This is to prevent the mold resin 70 from being divided because the groove is the through hole 84. Note that the through hole 84 as in the present embodiment can also be formed by die machining, cutting, or the like, similar to the groove 80 in the first embodiment.

  Here, FIG. 8 is a schematic cross-sectional view showing a state in which the grease 210 and the insulating substrate 220 are assembled to the semiconductor device 101 of the present embodiment. The semiconductor device 101 of the present embodiment can also be manufactured in the same manner as in the first embodiment.

  Then, as shown in FIG. 8, grease 210 is applied to the outside of the heat radiation surfaces 30 b and 40 b of the first and second heat radiation plates 30 and 40, and an insulating substrate 220 is further provided. Thereafter, similarly to the first embodiment, the cooling device 200 (not shown) is pressed and brought into contact with the outside of the heat radiation surfaces 30b and 40b via the grease 210 and the insulating substrate 220. Thus, the semiconductor device 101 is assembled to the cooling device 200 also in this embodiment.

  Also according to the present embodiment, since the groove 84 lying between the heat radiation plates 31 and 32 having different potentials is provided on the surface of the mold resin 70, the creeping distance can be increased as compared with the conventional case, and the above described Such overflowing grease 210 can be received. Therefore, it is possible to prevent the grease 210 provided on one of the heat radiation plates 31 and 32 having different potentials from contacting the grease 210 provided on the other.

  Moreover, in this embodiment, since the groove is configured as the through hole 84 as described above, the bottom of the groove is opened, and foreign matter that has entered the groove is easily discharged toward the opened bottom. . That is, according to the present embodiment, it becomes easy to discharge foreign matter in the through hole 84 that is a groove, which is preferable in terms of ensuring insulation reliability as a groove.

  In addition, since the through hole 84 as the groove of the present embodiment has the stepped portion 85, as shown in FIG. 8, the grease 210 that flows into the through hole 84 when the semiconductor device 101 is assembled is removed from the stepped portion. Part 85 can be received. As a result, it is possible to prevent the grease 210 from dropping to the second heat radiation plate 40 side.

  Further, in FIG. 8, if the insulating substrate 220 is assembled to the first heat radiating plate 30 via the grease 210 before the insulating substrate 220 is assembled to the second heat radiating plate 40, The presence or absence of contact of the grease 210 between the first left radiator plate 31 and the first right radiator plate 32 can be confirmed from the appearance of the through hole 84 on the second radiator plate 40 side. is there.

  In the example shown in FIGS. 5 to 7, the step portion 85 is provided in the through hole 84. However, the through hole 84 as a groove in the present embodiment has such a step portion. It may be a through hole with no straight inner surface.

(Third embodiment)
FIG. 9 is a perspective view showing a single structure of the second heat sink 40 in the semiconductor device according to the third embodiment of the present invention. The semiconductor device of the present embodiment has a through hole as a groove in the second embodiment, similarly to the semiconductor device shown in FIGS. 5 to 7. In such a configuration, the second heat dissipation is performed. The difference is that the plate 40 is deformed.

  In the second embodiment, in the second heat radiating plate 40 as a single heat radiating plate having the same potential, an opening 40c is provided in the second heat radiating plate 40 in order to provide the through hole 84 as the groove. It was.

  Therefore, as shown in FIG. 5, the width of the second heat sink 40 in the direction orthogonal to the arrangement direction of the heat sinks 31 and 32 having different potentials is larger than the width of the first heat sinks 31 and 32. Was also big. Conversely, in order to maintain the miniaturization of the physique of the semiconductor device, the width of the first heat radiation plates 31 and 32 must be suppressed within the limited width of the second heat radiation plate 40. Come.

  On the other hand, in this embodiment, as shown in FIG. 9, the two connecting portions 40 d that connect the through holes 84 in the second heat radiating plate 40 are replaced with the heat radiating surface of the second heat radiating plate 40. In the plane parallel to 40b, it projects outward from the heat radiating surface 40b.

  And the part pinched by these two connection parts 40d is the opening part 40c in the 2nd heat sink 40 so that the through-hole 84 may pass through this opening part 40c similarly to the said 2nd Embodiment. It has become. That is, the connecting portion 40d is in a position that avoids the through hole 84 and does not interfere with the through hole 84. Although not shown, the connecting portion 40d is sealed with the mold resin 70 in order to ensure electrical insulation.

  Here, the connecting portion 40d may be formed by integral molding by pressing or the like, or may be a separate body by welding or soldering. That is, the second heat radiating plate 40 of the present embodiment may be formed integrally from a single plate material, or the connecting portion 40d and the portions on both sides thereof are joined separately. It may be.

  According to this embodiment, the same effect as the second embodiment is exhibited. Further, according to the present embodiment, the connecting portion 40d in the second heat radiating plate 40 protrudes outside the heat radiating surface 40b in a plane parallel to the heat radiating surface 40b of the second heat radiating plate 40. The hole 84 can be made as large as possible.

  The fact that the through hole 84 can be enlarged means that the heat radiating surface 30b of the first left heat radiating plate 31 and the first right heat radiating plate 32 facing each other with the through hole 84 interposed therebetween on the first heat radiating plate 30 side. It leads to being able to grow. As a result, the heat dissipation surface 30b of the first heat dissipation plate 30 is enlarged.

(Other embodiments)
In the example shown in FIGS. 1 to 3, the groove 80 has a direction in which the heat radiation plates 31 and 32 having different potentials face each other on the surface of the mold resin 70 positioned between the heat radiation plates 31 and 32 having different potentials. However, the groove 80 having a cross-sectional shape as shown in FIG. 2 may be provided only in a part between the both end portions.

  1 to 3, an aggregate of three grooves 81 to 83 has been cited as the groove 80 composed of a plurality of grooves 81 to 83. Two grooves may be arranged in parallel, or four or more grooves may be arranged in parallel.

  Further, when three or more grooves are provided as grooves, for example, when an aggregate of five grooves is formed, two grooves located on the center side are each one groove located on both sides thereof. The configuration may be deeper than that. Furthermore, when the said groove | channel is comprised with a some groove | channel and the mutual depth is changed, the thing of a center part side may be shallower than the thing of the both sides.

  Further, when the groove 80 is constituted by a plurality of grooves 81 to 83, in FIGS. 1 to 3, the plurality of grooves 81 to 83 are adjacent to each other without a gap, but as shown in FIG. Individual grooves 81, 82, 83 may be arranged separately.

  Further, depending on the number and arrangement of the semiconductor elements described above, the circuit configuration formed between the first heat sink 30 and the second heat sink 40 also differs. Then, not only one of the first heat radiating plate 30 and the second heat radiating plate 40 but both may be constituted by a plurality of heat radiating plates having different potentials. In this case, the groove 80 may be provided between adjacent heat sinks of different potentials on the first heat sink 30 side and the second heat sink 40 side.

  Moreover, when both the 1st heat sink 30 and the 2nd heat sink 40 are comprised from several heat sinks from which an electric potential differs, the site | part located between the heat sinks of different electric potential among the surfaces of the mold resin 70 However, if the first heat radiating plate 30 side and the second heat radiating plate 40 side are at the same position, that is, the overlapping position, a through hole that connects these two portions may be formed in the mold resin 70. And this through-hole may be used also as the groove | channel on the 1st heat sink side and the groove | channel on the 2nd heat sink side.

  In each of the above embodiments, the first heat radiating plate 30 is composed of two heat radiating plates 31 and 32 having different potentials. However, the first heat radiating plate 30 has three or more different potentials. You may be comprised as the aggregate | assembly of a heat sink. In this case, a groove similar to the above may be provided between the adjacent heat dissipating plates of different potentials. This is the same even when the second heat radiating plate is composed of a plurality of heat radiating plates having different potentials.

  Furthermore, as a semiconductor element sandwiched between the first and second heat sinks 30 and 40, as long as these heat sinks 30 and 40 can be used as electrodes or heat dissipating members, they are not the IGBT 10 or the FWD 20 described above. For example, a MOS transistor or the like may be used. Moreover, the number of semiconductor elements should just be plural, and is not limited to the said embodiment.

  Further, as described above, the block body 60 is interposed between the semiconductor elements 10 and 20 and the first and second heat sinks 30 and 40 and has a role of ensuring the height between them. However, if possible, in each of the above embodiments, the block body 60 may not exist.

1 is a schematic plan view of a semiconductor device according to a first embodiment of the present invention. It is a schematic sectional drawing in alignment with the AA in FIG. FIG. 3 is a bottom plan view of FIG. 2. It is a schematic sectional drawing which shows the state which attached the semiconductor device of the said 1st Embodiment to the cooling device. It is a schematic plan view of the semiconductor device which concerns on 2nd Embodiment of this invention. It is a schematic sectional drawing in alignment with the BB line in FIG. FIG. 7 is a bottom plan view of FIG. 6. It is a schematic sectional drawing which shows the state which assembled | attached the grease and the insulated substrate to the semiconductor device of the said 2nd Embodiment. It is a perspective view which shows the single-piece | unit structure of the 2nd heat sink in the semiconductor device which concerns on 3rd Embodiment of this invention. It is a schematic sectional drawing which shows other embodiment.

Explanation of symbols

10 ... IGBT as a semiconductor element, 20 ... FWD as a semiconductor element,
30 ... 1st heat sink, 30a ... Inner surface of 1st heat sink,
30b ... the heat radiation surface of the first heat radiation plate,
31 ... 1st left-hand side heat sink as a heat sink with different electric potential,
32 ... 1st right side heat sink as a heat sink with different electric potential, 40 ... 2nd heat sink,
40a ... inner surface of the second heat radiating plate, 40b ... heat radiating surface of the second heat radiating plate, 40d ... connection portion,
70 ... Mold resin, 80 ... Groove, 81-83 ... Multiple grooves,
84 ... Through hole as a groove, 85 ... Step part.

Claims (8)

A plurality of semiconductor elements (10, 20) are sandwiched between the first heat radiating plate (30) and the second heat radiating plate (40) facing each other on the inner surfaces (30a, 40a),
The first and second heat sinks (30, 40) and the respective semiconductor elements (10, 20) are electrically and thermally connected;
The first and second heat radiating plates (30, 40) and the semiconductor element (10, 20) are encapsulated with a mold resin (70),
A semiconductor device in which outer surfaces of the first and second heat radiating plates (30, 40) opposite to the inner surfaces (30a, 40a) are exposed from the mold resin (70) as heat radiating surfaces (30b, 40b). In
At least one of the first and second heat radiating plates (30, 40) is composed of a plurality of heat radiating plates (31, 32) having different potentials.
On the surface of the mold resin (70) positioned between the heat sinks (31, 32) having different potentials, grooves (80, 84) are laid between the heat sinks (31, 32) having different potentials. A semiconductor device is provided. On the surface of the mold resin (70) located between the heat radiating plates (31, 32) having different potentials, the surface of the surface in a direction orthogonal to the direction in which the heat radiating plates (31, 32) having different potentials face each other. The semiconductor device according to claim 1, wherein the groove is provided so as to continuously traverse both ends. The semiconductor device according to claim 1, wherein the groove (80) is configured as a plurality of grooves (81 to 83) provided in parallel. The semiconductor device according to claim 3, wherein the plurality of grooves (81 to 83) are configured with different depths. The plurality of grooves (81-83) are provided in parallel with each other, and the groove (82) positioned on the center side among the plurality of grooves (81-83) The semiconductor device according to claim 4, wherein the semiconductor device is deeper than the grooves (81, 83) located on both sides of the groove (82) located on the center side. Of the first and second radiator plates (30, 40), the first radiator plate (30) is composed of a plurality of radiator plates (31, 32) having different potentials,
The groove extends from the first heat radiating plate (30) to the second heat radiating plate (40) in a portion of the mold resin (70) located between the heat radiating plates (31, 32) having different potentials. 2. The semiconductor device according to claim 1, wherein the semiconductor device is configured as a through hole (84) penetrating the mold resin (70) and the second heat radiating plate (40). A step is formed on the inner surface of the through hole (84) near the first heat radiating plate (30) so as to expand toward the opening of the through hole (84) on the first heat radiating plate (30) side. The semiconductor device according to claim 6, wherein a step portion (85) is provided. The connecting portion (40d) for connecting the through holes (84) in the second heat radiating plate (40) projects outward from the heat radiating surface (40b) of the second heat radiating plate (40). And
The semiconductor device according to claim 6 or 7, wherein the connecting portion (40d) is sealed with the mold resin (70).

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